Middleman config

config.ru

require 'rack'
require 'rack/contrib/try_static'

use Rack::Deflater

use Rack::TryStatic,
  root: 'build',
  urls: %w[/],
  try: ['.html', 'index.html', '/index.html']

run lambda{ |env|
  four_oh_four_page = File.expand_path("../build/404/index.html", __FILE__)
  [ 404, { 'Content-Type'  => 'text/html'}, [ File.read(four_oh_four_page) ]]
}

Gemfile

# If you have OpenSSL installed, we recommend updating
# the following line to use "https"
source 'https://rubygems.org'

ruby "2.1.0"

gem "middleman", "~> 3.1.0"
gem "middleman-blog"
gem "middleman-livereload"
gem "middleman-syntax"
gem "redcarpet"
gem "middleman-favicon-maker"

# For running on Heroku
gem "puma"
gem "rack-contrib"
gem "foreman"
gem "newrelic_rpm"

Procfile

web: bundle exec puma -p $PORT